A tiny ~700b centralized state container with component bindings for Preact. #reactjs #preact

  • { , , } store ({ count }) If actions is a function, it gets passed the store: ({ ( ) { { count . } }
  • , The above example as an Arrow Function: ({ count }) ({ count count }), ( ) { res ( ) { stuff .
  • , ) } }) ( , actions)( ({ count, increment }) ( div p Count {count} p button onClick {increment} Increment button div ) ) () ( Provider store {store} App Provider ) – – Creates a new store, which is a tiny evented state container.
  • Register a listener function to be called whenever state is changed.
  • If don’t, just open a new clear and descriptive issue.

unistore – 🌶 700b state container with component actions for Preact
Continue reading “A tiny ~700b centralized state container with component bindings for Preact.
#reactjs #preact”

Beginner’s guide to react/redux —painting a mental model

  • I highly recommend anyone starting out with Redux to read the core concepts outlined in the official documentation.Long story short, Redux application has a plain object, known as store, which serves as data model for your app.
  • For example, for a list of articles, I can have an article state that looks like this:state = { articles: [{ “id”: 314, “title”: “6 innovative apps utilizing the ethereum network”, “source”: “Investopedia‎”, “link”: “date”: “1500523200”, “type”: “msm” }, { “id”: 893, “title”: “what is plasma and how will it strengthen…”, “source”: “Investopedia‎”, “link”: “date”: “1502856000”, “type”: “msm” },.
  • In our article example, fetching articles is an action that looks that this:{ type: ‘ARTICLES_FETCHED’, payload: [{ “id”: 314, “title”: “6 innovative apps utilizing the ethereum network”, “source”: “Investopedia‎”, “link”: “date”: “1500523200”, “type”: “msm” }, { “id”: 893, “title”: “what is plasma and how will it strengthen…”, “source”: “Investopedia‎”, “link”: “date”: “1502856000”, “type”: “msm” },.
  • In our article example, the reducer looks like this:const initialState = { articlesById: null,}export default function(state = initialState, action) { switch (action.type) { case types.ARTICLES_FETCHED: return { …state, articlesById: action.articlesById } default: return initialState }}To summarize the basic ideas of Redux:it describes state as plain objects, and store (global state) by merging all the states in your app.it describes changes to the app as plain objects.it uses pure functions to handle changes.The redux API then bridges your redux logics with react views while providing some utilities to compose states.Say we send a request to a remote server and fetch some articles.
  • The reducer evaluates the action and store the payload articles in the state.

Disclaimer: This article is written by a beginner trying to comb through new concepts she just learned. React/Redux is the hottest frontend frameworks these day. If you google the term Redux diagram…
Continue reading “Beginner’s guide to react/redux —painting a mental model”

react-mobx-react-router-boilerplate

  • React, MobX, React-Router and Webpack boilerplate with async routes.
  • This boilerplate is also ready for deploying your app to Heroku.
  • Components are now loaded async with react-router-loader and the store is injected via MobX Provider.

React, MobX, React-Router, MobX-Router and Webpack (heroku-ready) boilerplate with async routes.
Continue reading “react-mobx-react-router-boilerplate”

Using Normalizr to organize data in stores — practical guide

Solve the issues with data organizing:  #ReactJS #JavaScript

  • Using Normalizr to organize data in stores — practical guideA React application usually needs some data from the server to be stored locally for immediate use, mainly to be shown on the page.
  • In the response for teachers we get something like this (shape of a server response): [ { students: [ { id, name, studentCourses: [ { studentId, courseId, grande, }, … ], }, … ], courses: [ { id, name, }, … ], }, … ]Here you can read about how to combine data in queries, if you also use Loopback.In this particular case this would spare us two requests, but this is not very useful if we speak about storing on front-end.
  • Secondly, we might need courses inside of a student entity instance, but when we make a query to the server, we don’t include these courses to avoid duplication.To cope with the described issues we can start with Normalizr — a utility that normalizes data with nested objects, just like in our case.
  • If you haven’t used redux-saga in your projects yet, I think this should convince you to do so.The first saga will fetch data:const urls = { teachers: ‘/teachers, students: ‘/students’, courses: ‘/courses’,};export function* fetchModel(model, ids, include) { const url = urls[model]; const where = {id: {inq: ids}}; const filter = {where, include}; const params = {filter}; return yield get({url, params});}The second will store the data:export function* queryModels(modelName, ids, include]) { const singleModelSchema = schema[modelName]; const denormalizedData = yield fetchModel(modelName, ids, include); const normalizedData = normalize(denormalizedData, [singleModelSchema]); const {entities} = normalizedData; yield a reducer will add new pieces of data to the already fetched ones:case ADD_ENTITIES: { const models = action.entities; const newState = cloneDeep(state); return mergeWith(newState, models);}Methods mergeWith and cloneDeep here are from lodash.Having done all that we can query data from server in this manner (selector):export function* fetchTeachers() { yield queryModels(‘teachers’, ids, [ { relation: ‘students’, scope: { include: [‘studentCourses’], } }, { relation: ‘courses’, } ]);}Normalizr uses a normalization schema as described here.Eventually we end up with the state that looks like this: state: { … models: { teachers: {…}, sudents: {…}, courses: {…}, studentCourses: {…}, }, … }This basically is a nice little copy of a part of our database in the store.
  • It is done in queryModels saga and we always know where the fetched data is going to be put.After that we can use it in any page of the app combing it in selectors as required.In our case, if needed, we can get an object for teacher as complicated as this (denormalized data): { students: [ { id, name, studentCourses: […], courses: […], }, … ], courses: [ { id, name, sudents: […], teachers: […], }, … ], }There is also another way.

In one of the projects, we encountered the issues with data organizing. To cope with that we can use Normalizr — a utility that normalizes data with nested objects.
Continue reading “Using Normalizr to organize data in stores — practical guide”

Using Normalizr to organize data in stores — practical guide

Solve the issues with data organizing:  #ReactJS #JavaScript

  • Using Normalizr to organize data in stores — practical guideA React application usually needs some data from the server to be stored locally for immediate use, mainly to be shown on the page.
  • In the response for teachers we get something like this (shape of a server response): [ { students: [ { id, name, studentCourses: [ { studentId, courseId, grande, }, … ], }, … ], courses: [ { id, name, }, … ], }, … ]Here you can read about how to combine data in queries, if you also use Loopback.In this particular case this would spare us two requests, but this is not very useful if we speak about storing on front-end.
  • Secondly, we might need courses inside of a student entity instance, but when we make a query to the server, we don’t include these courses to avoid duplication.To cope with the described issues we can start with Normalizr — a utility that normalizes data with nested objects, just like in our case.
  • If you haven’t used redux-saga in your projects yet, I think this should convince you to do so.The first saga will fetch data:const urls = { teachers: ‘/teachers, students: ‘/students’, courses: ‘/courses’,};export function* fetchModel(model, ids, include) { const url = urls[model]; const where = {id: {inq: ids}}; const filter = {where, include}; const params = {filter}; return yield get({url, params});}The second will store the data:export function* queryModels(modelName, ids, include]) { const singleModelSchema = schema[modelName]; const denormalizedData = yield fetchModel(modelName, ids, include); const normalizedData = normalize(denormalizedData, [singleModelSchema]); const {entities} = normalizedData; yield a reducer will add new pieces of data to the already fetched ones:case ADD_ENTITIES: { const models = action.entities; const newState = cloneDeep(state); return mergeWith(newState, models);}Methods mergeWith and cloneDeep here are from lodash.Having done all that we can query data from server in this manner (selector):export function* fetchTeachers() { yield queryModels(‘teachers’, ids, [ { relation: ‘students’, scope: { include: [‘studentCourses’], } }, { relation: ‘courses’, } ]);}Normalizr uses a normalization schema as described here.Eventually we end up with the state that looks like this: state: { … models: { teachers: {…}, sudents: {…}, courses: {…}, studentCourses: {…}, }, … }This basically is a nice little copy of a part of our database in the store.
  • It is done in queryModels saga and we always know where the fetched data is going to be put.After that we can use it in any page of the app combing it in selectors as required.In our case, if needed, we can get an object for teacher as complicated as this (denormalized data): { students: [ { id, name, studentCourses: […], courses: […], }, … ], courses: [ { id, name, sudents: […], teachers: […], }, … ], }There is also another way.

In one of the projects, we encountered the issues with data organizing. To cope with that we can use Normalizr — a utility that normalizes data with nested objects.
Continue reading “Using Normalizr to organize data in stores — practical guide”

Open-sourcing our #Redux library to sync parts of store state with cookies: #javascript #reactjs #webdev #opensource

  • redux-cookies-middleware is a Redux middleware which watches for changes in Redux state & stores them in browser cookie.
  • Use dot-notation to specify the path of the subsets of the store that has to be synced with cookies.
  • Consider a store with the following shape as an example:

    To sync the auth and with cookies, pass the following object to the middleware:

    { session { name name of the cookie in which the value of session will be synced }, { name name of the cookie in which the value of auth.token will be synced } }

    Value of the path object is another object that takes more configuration options:

    An object of common options for the middleware.

  • It basically takes , reads the synced state from cookies and merges it with the initial state of your application.
  • ( , ( , ) { initialState { auth { token , key }, session }; read stored data in cookies and merge it with the initial state initialState (initialState, paths, ( , ) (req, name)); create store with data stored in cookies merged with the initial state ( reducer, initialState, ([ ( paths, { ( , ) (res, name, value) } ) ]) ); .

redux-cookies-middleware is a Redux middleware which syncs a subset of your Redux store state with cookies.
Continue reading “Open-sourcing our #Redux library to sync parts of store state with cookies: #javascript #reactjs #webdev #opensource”

Using Normalizr to organize data in stores — practical guide

Using Normalizr to organize data in stores — practical guide  #reactjs

  • Using Normalizr to organize data in stores — practical guideA React application usually needs some data from the server to be stored locally for immediate use, mainly to be shown on the page.
  • In the response for teachers we get something like this (shape of a server response): [ { students: [ { id, name, studentCourses: [ { studentId, courseId, grande, }, … ], }, … ], courses: [ { id, name, }, … ], }, … ]Here you can read about how to combine data in queries, if you also use Loopback.In this particular case this would spare us two requests, but this is not very useful if we speak about storing on front-end.
  • Secondly, we might need courses inside of a student entity instance, but when we make a query to the server, we don’t include these courses to avoid duplication.To cope with the described issues we can start with Normalizr — a utility that normalizes data with nested objects, just like in our case.
  • If you haven’t used redux-saga in your projects yet, I think this should convince you to do so.The first saga will fetch data:const urls = { teachers: ‘/teachers, students: ‘/students’, courses: ‘/courses’,};export function* fetchModel(model, ids, include) { const url = urls[model]; const where = {id: {inq: ids}}; const filter = {where, include}; const params = {filter}; return yield get({url, params});}The second will store the data:export function* queryModels(modelName, ids, include]) { const singleModelSchema = schema[modelName]; const denormalizedData = yield fetchModel(modelName, ids, include); const normalizedData = normalize(denormalizedData, [singleModelSchema]); const {entities} = normalizedData; yield a reducer will add new pieces of data to the already fetched ones:case ADD_ENTITIES: { const models = action.entities; const newState = cloneDeep(state); return mergeWith(newState, models);}Methods mergeWith and cloneDeep here are from lodash.Having done all that we can query data from server in this manner (selector):export function* fetchTeachers() { yield queryModels(‘teachers’, ids, [ { relation: ‘students’, scope: { include: [‘studentCourses’], } }, { relation: ‘courses’, } ]);}Normalizr uses a normalization schema as described here.Eventually we end up with the state that looks like this: state: { … models: { teachers: {…}, sudents: {…}, courses: {…}, studentCourses: {…}, }, … }This basically is a nice little copy of a part of our database in the store.
  • It is done in queryModels saga and we always know where the fetched data is going to be put.After that we can use it in any page of the app combing it in selectors as required.In our case, if needed, we can get an object for teacher as complicated as this (denormalized data): { students: [ { id, name, studentCourses: […], courses: […], }, … ], courses: [ { id, name, sudents: […], teachers: […], }, … ], }There is also another way.

In one of the projects, we encountered the issues with data organizing. To cope with that we can use Normalizr — a utility that normalizes data with nested objects.
Continue reading “Using Normalizr to organize data in stores — practical guide”